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c. T, DRAPER. METHOD. OF PROTECTIVELY COATING SHEET METAL CONTAINERS.

APPLICATION FILED JUNE 10, I916.

Patented July 20, 1920.

IN VEN TOR, [am/mi; Z'ZZFAFIX,

I TTORNEY STATES PATENT OFFICE.

CHARLES T. DRAPER, OF CLEVELAND, OHIO, ASSIGNOR TO THE DRAPER MANUFAC- TURING COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

METHOD OF PROTECTIVELY COATING SHEET-METAL CONTAINERS.

Specification of Letters Patent.

Patented July 20, 1920.

Application filed June 10, 1916. Serial No. 102,890.

containers and more particularly sheet metal barrels having threaded or machined bunghole openings and vents. The object of my invention is to coat thesheet iron members of the container protectively against rust, the attack of acids and other substances to which the barrel is likely to be subjected. The protective coating preferably consists of a covering of zinc, tin, lead, or other metals and alloys thereof, preferably by the process of dipping the cleaned and pickled members of the container in a bath of the molten metal. This process I may term metal coating, without regard to the particular metal or alloy employed. a

Previously it has been the practice to coat sheet metal containers and metal barrels by cleaning and dipping after the manner wellknown in the art. This results in the deposit of considerable protective metal in eX- cess of that actually required for safeguarding the barrel and its contents. Also, it involves considerable skill, and the process is slow, whereby the entire inner surface of the barrel may be coated, and in some instances it is found that the coating is not completely applied, while invariably there is left within the barrel an excess of molten metal that may not be poured therefrom. Finally, the bung-hole openings which must be somewhat accurately finished and threaded, become coated with the protective metal and thereby necessitating special attention for cleaning the accurately formed and threaded parts, before the barrel may be placed in use.

These disadvantages attendant upon the usual procedure, I have wholly eliminated by separately galvanizing the cylindrical shell, its closure members and the protective annular rims thereof, if the latter are used, or these may be electroplated as with copper, ifdesired. It is impracticable to galvanize these members prior to forming them respectively as acylindrical shell and 010- sure members therefor, for the reason that the welding or'seaming operation and the stamping of the closure members, together With the rolling of chimes for the barrel would disrupt or destroy the surface coating to a large extent and subject the iron body of the barrel to attack at numerous vulnerable points.

In order to prevent the undesirable coatmg of the threaded portions of the barrel such as the bung-hole and vent openings, these are sealed against contact with the bath of molten metal, as by placing screw caps thereon, which are preferably removed while the metal of the bath has cooled as little as possible, but after the galvanized members have been removed from said bath. Under these circumstances the threaded and accurately formed portions remainin their finished condition, and no cleaning operation is necessary.

My invention may be better explained by making reference to the accompanying sheet of drawings whereon Figure 1 illustrates in vertical cross-sectionthe cylindrical shell for a metallic barrel having its bung-hole opening sealed and ready to be cleaned and dipped. Fig. 2 shows the completed barrel partially broken away and in section at its corners. Fig. 3 illustrates in vertical section a preferred type of closure member adapted for the particular barrel shown, with its vent opening suitably sealed. Fig. 4.- shows in vertical section the protective annular ring preferably employed. Fig. 5 is an enlarged fragmentary view in cross-section showing the completed joint, and Fig. 6 is a similar view showin the annular joint with the protective ring omitted, as is customary with storage receptacles. Throughout the several figures of the drawings I have employed the same character of reference to indicate similar parts.

It will be understood at the outset that my invention not only is unrestricted to the particular galvanizing methods adopted but it is equally unrestricted to the details of structure herein shown and described. Accordingly, the cylindrical shell may be of any approved type and the closure members and protective annular oint coverings may rolled with two ribs (4 to form the bilge of the barrel. One end of the shell may be flanged as at if, if desired.

The closure therefor comprises an inset head of sheet metal Z) having rim 5 adapted to form a double locked joint with the rim or flange M. A malleable iron ring 0 having an overlapping flange 0 is adapted to stay and protect the annular joint if the barrel is to be used for shipping purposes.

It will be observed that the bung-hole opening is covered by a screw cap (Z, while the finished or threaded vent opening iscovered by a similar screw plug 6.

These several members are suitably cleaned in accordance with any well-known methods for protectively coating with zinc, tin or lead or alloys thereof, and they are then separately dipped in baths of molten metal to insure the adherence and surface alloy of a protective coat of the desired metal, after which the closure members are inserted within the shell and a suitable liquid tight joint is formed therebetwcen, such, for example, as is illustrated in I? 2, 5 and 6.

As a specific example, I may state that for galvanizing with zinc, the shells are cleaned first in successive baths of sulfuric and muriatic acid, after which they are placed in a bath of molten zinc for approximately one minute and upon being withdrawn from the bath, the screw caps (Z are immediately removed from the bung-hole openings. Similar treatment is accorded the closure members, but preferably the protective rings or rims c, if such are used, are electroplated as with copper, after which the members of the barrel are assembled and jointed as shown. A plastic sealing material Z) is often used.

In the annular jointing operation, some portion of the zinc will flake off, but this is provided for, either by the inclosing protective flange 0" of the ring 0, or by coating the entire joint with aluminum bronze, for example, if the ring 0 is to be omitted. Similarly, the metals tin or lead or alloys, may be applied to the sheet metal barrel whenever the contents require a different protective metal.

As an extreme precaution, furthermore, it may be desirable in some cases, to galvanize the completed annular joints.

From the foregoing it will be seen that my invention contemplates the separate protective coating of the sheet metal shell in an unheaded condition, so that all portions of the shell may equally be subjected to the metal. In this condition it is apparent that there is no excess of metal left, as when a complete barrel is galvanized. The closure members and rings may also be protectively coated more effectively and uniformly in unassembled condition, while the bung-hole and vent openings are readily guarded against the access of the metal in the mo bath; the sealing member being removed as soon as possible after the article is removed. from the bath. Under these circumstances 'a thinner and more economical coating of metal may be applied and the labor cost is reduced as compared with galvanizing the tions as may be made therein by mere skill,

the following i 1. The method of protectively coating sheet-metal containers having finished metallic portions, which consists in sealing the finished portions thereof, cleaning said container and dipping it to obtain exterior and interior immersion in molten metal until an adhering exterior and interior covering becomes attached thereto, and thereafter removing the sealing member while the adhering metal is still hot, substantially as set forth.

2. The method of protectively coating sheet metal containers having threaded metallic portions, which consists in sealing the threaded portions thereof, cleaning said container, dipping it to obtain exteriorand interior immersion in a bath of molten metal until an alloying exterior and interior covering adheres thereto, and removing the sealing member while the adhering metal is hot, substantially as set forth. 7 r

3. The method of metal coating sheetmetal barrels which consists in separately and completely immersing the unheaded cylindrical shell and its container-heads in a bath of molten metal, and thereafter assenr bling and uniting the barrel members, substantially as set forth.

4:. The method of protectively coating sheet-metal barrels, which consists in separately cleaning and completely immersing the open cylindrical shell and its closures in a bath of molten metal until an adhering exteriorly and interiorly applied coating of metal is obtained, assembling and annularly jointing said members, and protectively covering the annular joints, substantially as set forth.

5. The method of completing sheet-metal receptacles, which consists in galvanizing completely the unheaded cylindrical shell,

inserting and annularly jointing the end closures thereof, and concurrently covering the annular oints exteriorly with an electroplated metal ring, substantially as set forth.

6. The method of protectively coating and completing sheet-metal containers, which consists in separately forming the cylindrical shell and closure members, cleaning and completely immersing them in a bath of molten metal until an alloying eXteriorly and interiorly applied covering adheres thereto, applying the closure members to the shell, and forming annular liquid-tight joints therebetween, substantially as set forth.

7 The method of protectively coating and completing sheet-metal containers, which consists in separately'forming the cylindri-l cal shell thereof, the closure members and the protective rings, suitably treating the same and separately covering said elements completely with protective coatings of metal, and thereafter annularly" jointing the shell and closures and overturning the annular protective rims of the rings about the oints,

substantially as set forth.

8. The method of protectively coating, assembling and completing metallic containers, which consists in separately forming the cylindrical shell and shaping or stamping the closure or end members therefor, separately immersing them in a gal vanizing bath to secure complete exterior and interior coverings of protective metal for each member, and thereafter forming annular liquid-tight joints against a plastic medium between said shell and closures respectively, substantially as set forth.

9. The method of constructing metallic containers, which consists in separately forming a cylindrical body and stamping inset closure members therefor, separately immersing them in a galvanizing bath to secure complete exterior and interior covering of protective metal for each member, and thereafter forming annular liquid-tight joints between the body and closure members, substantially as set forth.

10. The method of constructing metallic containers, which consists in separately forming and treating a cylindrical shell and stamped inset end members therefor, separately immersing said elements in 'a galvanizing bath to secure complete exterior and interior uniform coverings of protective metal for each member, forming annular liquid-tight joints between the shell and end members, and finally galvanizing the completed joints, substantially as set forth.

In testimony whereof I do now afiix my signature in the presence of two witnesses. CHARLES T. DRAPER. [1,. s.] WVitnesses:

GEo. WYMAN, ALBERT LYNN LAWRENCE. 

